Hi, John & Debbie......I'd recommend Atwater-Donnelly at the Beacon Hill Coffeehouse on 4/22. Traditional, appalachian, some a cappella.
Husband & wife with guitars, mountain dulcimer, flute, banjo & a few other odds 'n ends, incl. "limberjacks" (see other thread). Authentic and very good - have seen them several times 'cause they're local.
Keep in touch when you get to Boston. Something's bound to develop.
......Tiger